British scientists given go-ahead for human-animal embryo research

Scientists in Britain have been given the go-ahead to create human-animal hybrid embryos for research.

Britain's fertility regulator the Human Fertilisation and Embryology Authority (HFEA) has approved applications from King's College London and Newcastle University to carry out the research.

This will allow them to create "cytoplasmic" embryos, where human cells are merged with eggs from animals such as cattle or rabbits.

These human-animal hybrid embryos will be used for research purposes and the scientists say such research could lead to therapies for diseases such as Parkinson's and Alzheimer's.

The HFEA licence committee says the two applications satisfied all the requirements of the law and they have been offered one-year research licenses to carry out the research; the research licenses are both subject to a series of detailed conditions.

A lengthy investigation was carried out by the HFEA including a public consultation which revealed that the public was generally in favour of allowing animal-human embryos for research.

Researchers aim to produce hybrids that are 99.9 percent human and 0.1 percent animal and this will involve transferring nuclei containing DNA from human cells to animal eggs which have had almost all their genetic information removed.

The resulting embryos are therefore mostly human, with a small animal component; stem cells, which can grow into different kinds of tissue, are then formed.

Dr. Lyle Armstrong, from Newcastle University says the long term objective of the research is to understand reprogramming and find better ways to make human embryonic stem cells.

Dr. Armstrong says cow eggs appear to be as good as human eggs for this purpose once their own nuclear DNA is removed and replaced with DNA from a human cell and they are much more readily available.

Until now scientists have had to rely on human eggs left over from fertility treatment, which are in short supply and are often of poor quality.

The scientists say the only "animal" element which remains is the tiny amount of DNA housed in the mitochondria, the rod-like power plants outside the cell nucleus that generate energy.

The embryos could provide the researchers with a large supply of stem cells to work with; stem cells are "master cells", capable of reproducing into any cell of the body.

Professor Robin Lovell-Badge, head of stem cell biology at the Medical Research Council, says the HFEA's approval will provide additions to the arsenal of techniques UK scientists can now use.

He says it is logical to use animal eggs to refine techniques and the research will provide better understanding and eventually the development of therapies for a wide range of devastating genetic diseases.

However some opponents condemn the HFEA's decision and say it threatens human dignity.

In the United States President George W. Bush has on two occasions vetoed a bill which would allow federal funds for stem cell research as it would involve human embryo destruction which is a highly sensitive issue there for both political and religious reasons.

The team at King's, will be led by Dr. Stephen Minger.

The HFEA was set up in 1991 to license and monitor UK research centres, clinics and hospitals, that carry out research and treatments to do with IVF (in vitro fertilization), DI (donor insemination), and research involving human embryos; they also regulate the storage of human eggs, sperm and embryos.